/*

 * Licensed to the Apache Software Foundation (ASF) under one

 * or more contributor license agreements.  See the NOTICE file

 * distributed with this work for additional information

 * regarding copyright ownership.  The ASF licenses this file

 * to you under the Apache License, Version 2.0 (the

 * "License"); you may not use this file except in compliance

 * with the License.  You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

package com.bff.gaia.unified.sdk.transforms.windowing;



import com.bff.gaia.unified.sdk.coders.Coder;

import org.joda.time.Instant;



import java.util.Collection;



/**

 * A {@link WindowFn} that represents an invalid pipeline state.

 *

 * @param <W> window type

 */

public class InvalidWindows<W extends BoundedWindow> extends WindowFn<Object, W> {

  private String cause;

  private WindowFn<?, W> originalWindowFn;



  public InvalidWindows(String cause, WindowFn<?, W> originalWindowFn) {

    this.originalWindowFn = originalWindowFn;

    this.cause = cause;

  }



  /** Returns the reason that this {@link WindowFn} is invalid. */

  public String getCause() {

    return cause;

  }



  /** Returns the original windowFn that this InvalidWindows replaced. */

  public WindowFn<?, W> getOriginalWindowFn() {

    return originalWindowFn;

  }



  @Override

  public Collection<W> assignWindows(AssignContext c) {

    throw new UnsupportedOperationException();

  }



  @Override

  public void mergeWindows(MergeContext c) {

    throw new UnsupportedOperationException();

  }



  @Override

  public Coder<W> windowCoder() {

    return originalWindowFn.windowCoder();

  }



  /** {@code InvalidWindows} objects with the same {@code originalWindowFn} are compatible. */

  @Override

  public boolean isCompatible(WindowFn<?, ?> other) {

    return getClass() == other.getClass()

        && getOriginalWindowFn().isCompatible(((InvalidWindows<?>) other).getOriginalWindowFn());

  }



  @Override

  public void verifyCompatibility(WindowFn<?, ?> other) throws IncompatibleWindowException {

    if (!this.isCompatible(other)) {

      throw new IncompatibleWindowException(

          other,

          String.format(

              "Only %s objects with the same originalWindowFn are compatible.",

              InvalidWindows.class.getSimpleName()));

    }

  }



  @Override

  public WindowMappingFn<W> getDefaultWindowMappingFn() {

    throw new UnsupportedOperationException("InvalidWindows is not allowed in side inputs");

  }



  @Override

  public Instant getOutputTime(Instant inputTimestamp, W window) {

    return inputTimestamp;

  }

}